1. Field of the Invention
The present invention relates generally to an exercise device and, in particular, to an exercising device that advantageously requires the user to tense the upper body muscles only to an extent determined by the user.
2. Description of the Prior Art
The prior art discloses many forms of exercising devices for the upper torso in which elastic parts or straps require the user's arms to move away from the body against or counter to a biasing force.
In U.S. Pat. No. 5,518,481 a continuous elastic cord is adapted to be looped around a user's shoulder. Handgrips at each cord end are grasped and the upper body is exercised against the biasing resistance of the cord.
In U.S. Pat. No. 4,961,573 a boxing exercise harness is worn on the upper torso and includes handgrips, a pulley system and interposed elastic straps. The user performs a boxing routine and an elastic force provided by the straps opposes the arm movements.
In U.S. Pat. No. 5,433,688, elastic cords having a handgrip at each end are attached to a waist belt. The user's arm and upper body are moved against the resistance of the elastic cords.
In U.S. Pat. No. 5,473,435, the user wears a belt to which is attached a pair of swivel assemblies having coupled thereto counterforce units that provide an elastic biasing force for performing arm curls.
In UK Patent No. 434,067, shoulder straps extend from a belt and have coupled thereto springs having foot engaging loops for developing the muscles of the arm, chest and back.
In U.S. Pat. No. 4,911,439 an elastic cord is looped around the shoulders of a user and handles attached to the cord are grasped. The user exercises by stretching the cord.
In U.S. Pat. No. 4,993,705, an expandable strap having wrist cuffs is attached to a vest. Arm movements exert a pulling force on the strap.
Exercising devices of the foregoing types are oftentimes complicated but, more importantly, require constant expanding and contracting of the user's arms thereby causing arm weariness and the magnitude of tension is normally not dictated by the user but the parameters of the elastic member.